The YL-69 (or HL-69)
The YL-69 (or HL-69) soil moisture sensor is a widely used sensor designed to measure the moisture level in soil, making it ideal for applications like automated irrigation systems, gardening, and environmental monitoring. This sensor consists of two main components: a probe that is inserted into the soil to detect its moisture level, and a control circuit that converts the moisture content into a readable signal.
The sensor works by using the resistance between the two probes: when the soil is dry, the resistance is higher, and when the soil is wet, the resistance decreases. The sensor outputs an analog signal, which corresponds to the moisture level. In addition to the analog output, the YL-69/HL-69 module also features a digital output that can be used for simple threshold-based applications—such as triggering an alert when the soil becomes too dry or activating a pump for irrigation when moisture falls below a certain level.
The analog output can be read by a microcontroller like Arduino, which allows for continuous monitoring of soil moisture. Users can adjust the sensitivity of the sensor using a potentiometer on the module, enabling fine-tuning for different soil types and moisture requirements. While it is a relatively inexpensive and easy-to-use sensor, the YL-69/HL-69 does require occasional calibration and can be affected by soil salinity, making it best suited for basic moisture sensing applications in home gardening and agriculture.
The sensor works by using the resistance between the two probes: when the soil is dry, the resistance is higher, and when the soil is wet, the resistance decreases. The sensor outputs an analog signal, which corresponds to the moisture level. In addition to the analog output, the YL-69/HL-69 module also features a digital output that can be used for simple threshold-based applications—such as triggering an alert when the soil becomes too dry or activating a pump for irrigation when moisture falls below a certain level.
The analog output can be read by a microcontroller like Arduino, which allows for continuous monitoring of soil moisture. Users can adjust the sensitivity of the sensor using a potentiometer on the module, enabling fine-tuning for different soil types and moisture requirements. While it is a relatively inexpensive and easy-to-use sensor, the YL-69/HL-69 does require occasional calibration and can be affected by soil salinity, making it best suited for basic moisture sensing applications in home gardening and agriculture.
